DESCRIPTION: In this renewal proposal it is stated that the major objective in this research is to make significant contributions to organic chemistry and medicine through synthetic studies on physiologically active natural and man-made organic compounds, including 1. Palytoxin: Total Synthesis, Preferred Local and Global Conformation, Preparation of Radioactively Labelled PTX, and Preparation of Affinity Column, 2. Conformational Analysis of C- and O- Glycosides: Human Blood antigens, 6-O-Methyl-D-glucose containing Lipopolysaccharides (MGLP) and 3-O-methylmannose-containing Polysaccharides (MMP), and C-Trehaloses, 3. Chemical Ruler: Conformational Analysis of Fatty Acids and Their Derivatives; Design and Synthesis of Large Organic Molecules with Ion Channel-like Assemblies; Stereochemistry Assignment of Maitotoxin, 4. Structure Elucidation and Synthesis of AAL toxins and Fumonisins, 5. Ni(II)/Cr(II)-Mediated Coupling Reaction: Asymmetric Process, 6. Tripodal Ligand Chemistry: Enterobactin analogs and others, and 7. Total Synthesis of Batrachotoxin and Aranotin. The principal investigator notes that the power of organic chemistry is most effectively extended by challenging complex systems, and much of the progress of medicine critically depends upon the extension of the power of organic chemistry. He further states that it is also his specific objective to develop practical and efficient syntheses of certain natural products and their analogs which have high physiological activity, but are not available in appreciable amounts from natural sources. He expects that these studies are to stimulate progress in medicine.